Trevor Bayne has been diagnosed with multiple sclerosis but will continue to race in NASCAR.

The Roush Fenway Racing driver was cleared by doctors and NASCAR after extensive testing at the Mayo Clinic in Minnesota. Bayne said Tuesday he isn't taking medication and expects no changes in lifestyle.

He said he has experienced no symptoms since being sidelined for two months after numbness in his arm during a race at Texas Motor Speedway. That prompted Bayne's first trip to the Mayo Clinic, and his continued checkups led to doctors deciding he had MS.

Bayne had symptoms of blurred vision, nausea and fatigue, which led doctors initially to conclude he might have Lyme Disease on his elbow. Bayne said he learned he had MS this summer, a few weeks after winning at Iowa Speedway.

"I don't know if the two are connected," he said. "I'm not a doctor and I wouldn't want to make that call, but they wanted to do more research because I wasn't satisfied with not knowing as a competitive person and as a racer. We want to know how everything works and causes and effects, so I just kept going back."

Roush Fenway Racing president Steve Newmark said it was Bayne's decision to reveal the news, and that it didn't impact his status with sponsors or the team.

"He was completely fine and cleared after it and the reality of it is if Trevor wasn't a race car driver and didn't have the means, he probably would never have been diagnosed," Newmark said. "It was through his determination of just regularly getting checked that it came to light."

Bayne, 22, became an overnight sensation in 2011 when he became the youngest winner of the Daytona 500, triumphing with the fabled Wood Brothers Racing team in only his second start in NASCAR's premier series.

"There are a lot more people in our community and in our world that can relate to somebody who is going through hard times and somebody who is winning races, who is winning championships, who has won the Daytona 500, who looks like he has it all together," said Bayne, who was married in June. "It looks like everything is going great, but how many people can relate to that? So, for me, going through something hard, that shows our true character."

Bayne, whose younger sister also has MS, has driven full time in the Nationwide Series this season and is ranked sixth in the standings with 20 top 10s in 32 starts. He said the diagnosis lifted a weight off his shoulders, but the uncertainty hadn't impacted his performance.

"What's impacted our season the most is how competitive the Nationwide Series is this year and how tough some of the competitors are," he said. "I feel like we've got to step up our game a little bit and get our cars a little better. I don't think it's the season any of us would have hoped for, but we've had some bright lights also with a win at Iowa."

Bayne also has continued to race part time in Cup with Wood Brothers Racing, posting three top 10 starts in 45 starts from 2010-13.

"I've never been more driven to compete," he said. "My goals are the same as they've been since I started racing. I want to compete at the highest level and I want to win races and championships. I am in the best shape I've ever been in, and I feel good. I'm committed to continuing to take the best care of my body as possible."

The Knoxville, Tenn., native won't be the first driver to race with MS in a NASCAR national series. Kelly Sutton, who was diagnosed with MS as a teenager, made 54 starts in the Camping World Truck Series from 2003-07.

Bayne will drive full-time in the No. 6 Ford Mustang during the 2014 Nationwide Series season.

"We are 100 percent supportive of Trevor and his ability to compete in a race car," Roush Fenway team owner Jack Roush said in the release. "I have full confidence in Trevor and his partners have all expressed that same confidence and support. As with all of our drivers, we look forward to standing behind Trevor and providing him with all of the tools he needs as he continues to develop in his young career."